Background: I have a G-Technology 2TB external drive model "Q 2TB with eSata, USB2.0, Firewire 400, Firewire 800 interfaces," "0G00203". I have been using it with a PC. I originally formatted it for the PC. I now have an iMac, Mountain Lion and want to transfer the data to the iMac and then reformat the external for use with the iMac.

Problem: I have purchased a FireWire800 cable and plugged it into the G-Technology drive. To that, I have an Apple Thunderbolt Firewire Adapter attached and have connected that to the iMac Thunderbolt port in the rear of the computer. I assuming that is the correct way to do it.

However, I cannot find the G-Technology drive on my computer. It is not showing up. I have gone to Preferences under Finder and checked Hard Disk but it still doesn't show up. I am assuming that is because I have it formatted for the PC. How do I find it so I can move all the files from the G-Tech drive to the iMac internal drive, which is 3TB so it can handle it?

Thanks for posting. You were close, in finder preferences you need to select external disks. Although even if that is not checked you should be able to find the drive listed in finder under devices in the pane on the left under favorites. If the drive is formatted into NTFS it should mount automatically. Mac can read from it but cannot write to it. Please let me know if this works for you.

I did have External Disk checked (sorry I stated it incorrectly in my original email). Actually at first, I had both hard disks and external disks checked. The hard disk ( the Mac's internal) did show up on the desk top, but still no G-tech drive. It does not show up under Devices on the left of the Finder screen either.

When I originally formatted the external drive several years ago, I followed the G-technology directions so I assume it is formatted in the N... format that you stated. I used an eSata connection at that time with the PC.

I don't remember getting a FireWire cable with the G drive, but the box says one was included. I could not find it among my cable collection so I purchased a "4mac, FireWire 9pin /800 to 9pin/800" and the "Apple Thunderbolt to FireWire Adapter" and connected it to the Thunderbolt port on the 2012 iMac, which is the only port it fit into it so, I'm assuming I did that correctly.

I know I've repeated some information in my earlier question, just trying to be thorough and get all the facts in this reply.

If you are having trouble with the firewire connection you may want to see if it will be read on usb. You can also check to see if the drive is listed in disk utility. You can find it under applications in the utilities folder.

Thank you for the response. I will try the usb connection. If that doesn't work, I will take it to the Apple Genius Bar and see if they can help. If that doesn't work, I will get a professional to move my data to the iMac via whatever means they use to go from PC to Mac. I appreciate your help.

Thanks for posting. If disk utility is unable to repair the drive enough for a read only status I recommend a program called Data Rescue 3. It is one of the better data recovery programs on the market and has a high success rate. You can download a trial of the program to see if it can see the files if so it will prompt you to purchase the full software before you recover the files. The trial can be downloaded through cnet.